At present a collagenase consisting of a 1:1 mixture of Aux I and Aux II collagenases derived from clostridium histolyticum has been approved for use as a prescription medicine in the United States under the trademark Xiaflex® and in the European Union under the trademark Xiapex®. Current approved indications are for the treatment of adults suffering from Dupuytren contraction and for adult men who have Peyronies disease. In addition, this product is under clinical and pre-clinical investigation for a number of collagen lesion based human and veterinary applications such as frozen shoulder, human lipoma, canine lipoma, cellulite and uterine fibroids.
All of the aforesaid applications require local (lesion site) injection of the collagenase product. It is highly desirable that to achieve optimum clinical benefit that the collagenase remain at the lesion site for an extended period to allow the enzyme to work to maximum extent. However, the current commercial formulation of collagenase for injection is a solution prepared by reconstituting the lyophilized collagenase powder with buffered saline for injection. Data from a pharmacokinetic study has shown that a significant amount of collagenase in the commercial formulation is found in patient urine as early as thirty minutes post injection. This indicates that the administered collagenase may be washed away easily from the injection site at the lesion or other therapeutic targeted area. It is evident that formulations which provide longer residence time at the injection site can improve the therapeutic effect of the collagenase treatment.